Dead diction of tobacco would be the first step . Consult a Tii dentist
who would help you.Chewing gums with Xylitol
could help, salt water rinses, and mouthwashes could help, thorough brushing of teeth, consult dentist for Oral prophylaxis
, use fluoride
tooth paste, As far
as the red patch in your mouth is considered it will have to be examined before further comments.Consult your dentist.